Herding / Corralling

[historic_bruno]

Corrals are currently fairly useless in the game, they are only used to train animals to slaughter for meat. The details haven't been fully described so this is a first draft of how it could work:

• Herd animals can be captured and brought back to the player's corral (see #997/#1310). I guess this would be goats, sheep, and maybe horses/elephants (depending on the biome and player's civ?)
• The animals can just stand around the corral building, no need to show them physically inside it. Whether they are corralled or not could be based on distance from the structure. There could be limits per corral.
• Once at the corral, the animals begin providing steady resources to the player, probably food
• There can be bonuses for some animals and civs. For example having horses at the corral could provide cavalry training bonuses (lower cost, faster rate, or something).
• Animals can still be slaughtered for meat as before, but then the bonus they provide is lost.
• An enemy player can raid and capture the animals if unguarded, bringing them back to their own corral (or slaughter them)